Add extra prompts, endless generation, random character default, and small fixes

- Add extra positive/negative prompt textareas to all 9 detail pages with session persistence
- Add Endless generation button to all detail pages (continuous preview generation until stopped)
- Default character selector to "Random Character" on all secondary detail pages
- Fix queue clear endpoint (remove spurious auth check)
- Refactor app.py into routes/ and services/ modules
- Update CLAUDE.md with new architecture documentation
- Various data file updates and cleanup

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

data/scenes/mysterious_4lch3my_sh0p_i.json

@@ -1,6 +1,6 @@
 {
   "scene_id": "mysterious_4lch3my_sh0p_i",
-  "scene_name": "Mysterious 4Lch3My Sh0P I",
+  "scene_name": "Alchemy Shop",
   "description": "A dimly lit, mysterious alchemy shop filled with ancient books, glowing potions, and strange magical artifacts like preserved eyes and enchanted daggers.",
   "scene": {
     "background": "indoors, alchemy laboratory, cluttered, bookshelf, potion, glass bottle, spider web, stone wall, mist, shelves, ancient",
@@ -24,7 +24,7 @@
     "lora_name": "Illustrious/Backgrounds/mysterious_4lch3my_sh0p-i.safetensors",
     "lora_weight": 1.0,
     "lora_triggers": "mysterious 4lch3my sh0p",
-    "lora_weight_min": 1.0,
+    "lora_weight_min": 0.6,
     "lora_weight_max": 1.0
   },
   "tags": [
@@ -34,4 +34,4 @@
     "background",
     "magic shop"
   ]
-}
+}